The grand re-opening of the Noe Valley-Sally Brunn Branch Library drew such a big crowd on Saturday that it was hard to see where the $5.7 million in improvements had gone in the historic Carnegie building at 451 Jersey St.

Closed for two years, the library got a floor-to-ceiling makeover similar to those at other recently reopened branches across the city: accessible restrooms, expanded teen and children's areas, new elevator and lighting fixtures, restored furniture, more computers and free wireless Internet access.

One thing that was hard to miss was the spruced-up ornamental ceiling that greeted the throngs of people who danced to a live jazz band, snacked on Costco deli spreads and quickly stocked up on armfuls of new books and DVDs.

Mayor Gavin Newsom told the crowd at the ribbon-cutting ceremony that the building originally went up in 1916 for a mere $45,499.

"The good old days!" he laughed.

The big-budget face-lift was completed by Carey & Co. Architecture of San Francisco, with considerable input from the community. The project, which began in 2006, was delayed twice, with dramatic cost increases each time.

"We were really in a battle here," said District Eight Supervisor Bevan Dufty, who acted as an intermediary between anxious neighbors and overworked construction crews. "I didn't want to see a hatchet job. The most important thing was to see it done right."

The opening ceremonies also featured comments from City Librarian Luis Herrera, state Sen. Carole Migden and Assemblyman Mark Leno, among other officials and traditional Chinese lion dancers.

"I have specifically looked away during the renovations because I wanted the full impact of the change when I walked in," Leno said, although he would probably have to return in a few weeks to be able to see past all the bodies.

The Noe Valley-Sally Brunn Branch Library was among 17 city libraries in line for renovation under a $105.9 million bond measure approved by voters in 2000. Rejuvenated libraries have recently opened in the Marina, Glen Park and the Western Addition.

"There's nothing more important than for the public to see its dollars at work," Newsom said as he signed autographs and posed for pictures outside after the ceremony.

Despite ruffling feathers with community leaders by appearing in sweatpants and a baseball cap at the reopening of the Western Addition branch in February, Newsom wore the same outfit on Saturday. "That was for yoga," he said. "Today, Jennifer (Siebel, his fiancee) is moving in."

Earlier, Newsom had told the audience, "If you think I look strange today, just look at Supervisor Bevan Dufty."

Dufty, who wore shorts and a Havana shirt covered with spiders as he carried his napping 18-month-old daughter, Sidney, through the event, shrugged off the barb. "I told Gavin to show his legs," he said. "He's doing all these things like running Bay-to-Breakers and he never wears shorts. There must be something wrong with his legs."